#!/usr/bin/env bash
function remindx(){
  local COUNT="$#"
  local COMMAND="$1"
  local MESSAGE="$1"
  local OP="$2"
  # Display help if no parameters or help command
  if [[ $COUNT -eq 0 || "$COMMAND" == "help" || "$COMMAND" == "--help" || "$COMMAND" == "-h" ]]; then
    echo "COMMAND"
    echo "    remind <message> <time>"
    echo "    remind <command>"
    echo
    echo "DESCRIPTION"
    echo "    Displays notification at specified time"
    echo
    echo "EXAMPLES"
    echo '    remind "Hi there" now'
    echo '    remind "Time to wake up" in 5 minutes'
    echo '    remind "Dinner" in 1 hour'
    echo '    remind "Take a break" at noon'
    echo '    remind "Are you ready?" at 13:00'
    echo '    remind list'
    echo '    remind clear'
    echo '    remind help'
    echo
    return
  fi

  # Check presence of AT command
  if ! which at >/dev/null; then
    echo "remind: AT utility is required but not installed on your system. Install it with your package manager of choice, for example 'sudo apt install at'."
    return
  fi
  # Run commands: list, clear
  if [[ $COUNT -eq 1 ]]; then
    if [[ "$COMMAND" == "list" ]]; then
      at -l
    elif [[ "$COMMAND" == "clear" ]]; then
      at -r $(atq | cut -f1)
    else
      echo "remind: unknown command '$COMMAND'. Type 'remind' without any parameters to see syntax."
    fi
    return
  fi

  shift 2
  local WHEN="$@" 

  # Determine time of notification
  if [[ "$OP" == "in" ]]; then
    local TIME="now + $WHEN"
  elif [[ "$OP" == "at" ]]; then
    local TIME="$WHEN"
  elif [[ "$OP" == "now" ]]; then
    local TIME="now"
  else
    echo "remind: invalid time operator $OP"
    return
  fi
  # Schedule the notification
  echo "notify-send '$MESSAGE' -a 'Reminder' -i converseen -u critical" | at $TIME 2>/dev/null
  echo "Notification scheduled at $TIME"
}

remindx "$@"
